//// spectral toolkit // copyright (c) 2005 university corporation for atmospheric research// licensed under the gnu general public license//#ifndef __rfft3__#define __rfft3__#include "rfft2.h"#include "group.h"#include "fiber.h"namespace spectral{  /// Real symmetric three-dimensional FFT object.  Computes the normalized real symmetric 3-d FFT  /// and its inverse using multi-threaded transforms.  ///  /// The following example computes the forward and backward transforms on an array  /// of real values and compares the result with the original values.  Note the use of  /// the alias function template to map the input and output arrays to the same memory  /// locations.  In particular, note that the overall sizes of the input and output  /// arrays must be the same and the use of 2*(nz/2+1) as the leading dimension of  /// the real 3-d array used to alias to the complex array storing the spectral  /// coefficients.  /// \code  /// #include <iostream>  /// #include <rfft3.h>  /// #include <alloc.h>  /// #include <alias.h>  ///  /// using namespace spectral;  ///  /// int main()  /// {  ///   int nx=50,ny=60,nz=40;  ///   int threads=2;  ///   real ***a=alloc<real>(nx,ny,2*(nz/2+1));  ///   complex ***b=alias<complex,real>(nz/2+1,ny,nx,a);  ///   real ***c=alloc<real>(nx,ny,nz);  ///   rfft3 W(nx,ny,nz,threads);  ///   real dx=2.0/(real)nx;  ///   real dy=2.0/(real)ny;  ///   real dz=2.0/(real)ny;  ///   for(int i=0;i<nx;i++)  ///     for(int j=0;j<ny;j++)  ///       for(int k=0;k<nz;k++)  ///         a[i][j][k]=c[i][j][k]=(-2.0+i*dx)*(-2.0+k*dz)*(-2.0+j*dy);  ///   W.analysis(a,b);  ///   W.synthesis(b,a);  ///   real error=0.0;  ///   for(int i=0;i<nx;i++)  ///     for(int j=0;j<ny;j++)  ///       for(int k=0;k<nz;k++)  ///         error=max(error,fabs(a[i][j][k]-c[i][j][k]));  ///   std::cout << "error=" << error << std:: endl;  ///   dealloc<real>(a);  ///   dealias<complex>(b);  ///   dealloc<real>(c);  ///   return(0);  /// }  /// \endcode  ///  /// \sa cfft3  class rfft3  {  public:    rfft3(int,int,int,int);    rfft3(int,int,int);    ~rfft3();              void analysis(real ***,complex ***);    void synthesis(complex ***,real ***);    void analysis(real ****,complex ****,int);    void synthesis(complex ****,real ****,int);  private:    /// Internal thread object for rfft3    class thread : public fiber    {    public:      thread(int,int,int,rfft3*,int);      ~thread();                void analysis(real ****,complex ****,int);      void synthesis(complex ****,real ****,int);      void wait();    private:      group *g;      real ****A;      complex ****B;      complex ***C;      int n1,n2,n3,N3;      int m1,m32,p1,p32;      int M,P;      cfft *FFT1;      rfft2 *FFT2;      real fac;      void start();      enum method {ANALYSIS,SYNTHESIS} Method;      rfft3 *Parent;    };    complex ***C;    group *g;    int threads;    thread **t;    friend class thread;  };}#endif// Local Variables:// mode:C++// End: